When it comes to mountain biking, having a proper hydration pack is almost as essential as a helmet. For an all-around pack that has enough capacity to get you through all-day epics and years of use, look to the Dakine Session 12L Hydration Pack. With a women's specific fit, breathable Air Mesh back panels/shoulder straps, and enough space to haul some trail snacks, a spare layer, and your emergency bike kit, the popularity of the Session 12L Hydration Pack is well-deserved.